The goals of this Core are to support of the development and use of creative and appropriate research strategies in the study of social-level factors by CDUHR and other investigators. Plans for this Core include activities to aid investigators in the development of research projects and evaluation of potential sources of systematic bias, to review research findings with respect to their application to public health HIV prevention programs, to provide a forum for discussion of research methods in studying social-level influences, and to write reviews of methodologic issues and offer solutions to benefit other scientists.